The dash is a fascinating mark of punctuation because it is so commonly misunderstood both grammatically and typographically. To be clear, there are many kinds of dash-like characters:

• hyphen ( - )
• en dash ( – )
• em dash ( — )
• horizontal bar ( ― )
• underscore ( _ )
• tilde ( ~ )

This blog entry will focus on the dash as a mark of punctuation, which most often takes the form of the em dash (and should, as I will elucidate later).

When used properly, the em dash is sweeping, bold, and clear. When used improperly, it's a distraction at best and a source of confusion at worst. Let's take a look at the proper grammar and typography of our friend—the em dash!

Grammar

There are at least 4 approved uses of the dash:

1) To introduce a dramatic restatement or shift in tone.

a) Ex:

Sometimes I like to eat cake—and smash it all over my face!

2) To create an emphatic parenthetical, aside, or afterthought.

a) Ex:

My favorite Nintendo character is Kirby—the cutest pink puffball there is!—because he has the ability to take on the powers of his enemies.

b) Ex:

I wish Quinn would stop bothering me—funny though she is.

3) To informally introduce a list.

a) Ex:

Instead of bothering me—take out the garbage, do your homework, and clean the dishes.

4) To indicate an interruption.

a) Ex:

Quinn: "There's something odd about that space vortex, but—"

Peter: "It's swallowing me!"

b) Ex:

Kirby's favorite foods are tomato and—

Wait a sec, I left the car running.

Most of the confusion with the grammar of the dash comes from a misunderstanding of why it should be used. One should take care to make sure that the dramatic, sweeping effect of the dash is warranted. If it is used too frequently, the effect on the reader is jarring, as the sentence structure becomes disjointed.

a) Ex:

Choppy:
Quinn played Space Invaders all night—not to be outdone by Peter's score.

Better:
Quinn played Space Invaders all night so as not to be outdone by Peter's score.

b) Ex:

Choppy:
The brown fox jumped—quickly over the fence—on its way to the forest.

Better:
The brown fox jumped quickly over the fence on its way to the forest.

But a well-placed dash can be just the spice a sentence needs to enthrall the reader and make your message clear.

a) Ex:

Ok:
I could pour my heart on her and jam it down her throat; but it would do no good.

Better:
I could pour my heart on her—jam it down her throat—but it would do no good.

b) Ex:

Ok:
I called him over to talk about it, and we had some tea while sharing smiles and pleasantries (the treacherous snake).

Better:
I called him over to talk about it, and we had some tea while sharing smiles and pleasantries—the treacherous snake.

Typography

The other area in which the dash is often misunderstood is in its typography. The dash should be denoted by the em dash ( — ) with no spaces before or after, according to the 2003 MLA Manual. The em dash gets its name from a time in typesetting when the width of the capital letter M was the same as the width of the dash in the particular typeface and point size in which it was being used (Adobe glossary of typographic terms). Although widths have changed and the em unit no longer holds the same meaning, it is the preferred method for denoting the sweeping effect of the dash and separating it from other marks with their other meanings. If the medium in which you are working does not allow the em dash, one may denote it with two hyphens together, if the typeface makes the hyphens appear wide ( −− ), with no spaces before or after (see same MLA Manual) or three hyphens together, if the typeface makes the hyphens appear short ( --- ), with no spaces before or after.

The dash is often considered an informal mark of punctuation where the rules are relaxed. As such, otherwise well-meaning writers will often use whatever means with which their fancy strikes them to produce the mark. Although context may make their meaning clear, the problem with a lax approach is that it may lead to ambiguity or make such writings less credible to the discerning eyes of those who know better. In particular, the use of a single hyphen to indicate a dash is troubling.

a) Ex:

Wrong:
Peter's bedroom forces him to work poorly-lit only by a candle on his nightstand-he struggles for hours by his bedside.

Right:
Peter's bedroom forces him to work poorly—lit only by a candle on his nightstand—he struggles for hours by his bedside.

See the problem? The hyphen has its own distinct uses. In the "Wrong" example above, we may at first think that the writer is using the hyphen to combine the words poorly and lit into a single adjective. We may read the sentence twice before we understand, and if you're like me, your ire is increasing with every moment. Why should the writer stand in the way of our understanding and the material? Here's another example:

a) Ex:

Ambiguous:
"She's turning 21 – 10 or 11 years ago it was me – and she'll want a big party to celebrate."

Better:
"She's turning 21—10 or 11 years ago it was me—and she'll want a big party to celebrate."

With the "Ambiguous" example above I used an en dash and a space instead of a hyphen, but we see a similar issue as in the previous example. Because of the wording, it looks like I'm specifying a range of numbers. I could write out the numbers or reword the sentence to help avoid the issue, but why work around a mistake when I can simply correct it? It's essential that writers remain consistent in the way they write. If one begins by using informal marks for one's dashes, he or she may find him or herself dancing around problems later. It's better to start off doing it correctly from the start and not have to worry about editing oneself out of holes later!

Now that you have the knowledge of the proper uses and typography of the fascinating dash, you can keep your writing from harm. And don't hesitate to correct your friends!—better writing improves life for us all.